Efficacy of Ebselen Against Invasive Aspergillosis in a Murine Model

Invasive aspergillosis is one of the major causes of morbidity and mortality among invasive fungal infections. The search for new antifungal drugs becomes imperative when existing drugs are not able to efficiently treat these infections. Ebselen, is an organoselenium compound, already successfully approved in clinical trials as a repositioned drug for the treatment of bipolar disorder and prevention of noise-induced hearing loss. In this study, we aimed to reposition ebselen for the treatment of invasive aspergillosis by showing ebselen effectiveness in a murine model. For this, BALB/c mice were immunosuppressed and infected systemically with Aspergillus fumigatus. Animals were divided and treated with ebselen, voriconazole, or drug-free control, for four days. The kidneys were used for CFU count and, histopathological and cytokine analysis. Ebselen was able to significantly reduce the fungal burden in the kidneys of infected mice with efficacy comparable with voriconazole treatment as both had reductions to the same extent. The absence of hyphae and intact kidney tissue structure observed in the histopathological sections analyzed from treated groups corroborate with the downregulation of IL-6 and TNF. In summary, this study brings for the first time in vivo evidence of ebselen efficacy against invasive aspergillosis. Despite these promising results, more animal studies are warranted to evaluate the potential role of ebselen as an alternative option for the management of invasive aspergillosis in humans.

Evaluation of Antineoplasic Activity of Zingiber Officinale Essential Oil in the Colorectal Region of Wistar Rats

INTRODUCTION

Aberrant Crypt (AC) and Aberrant Crypt Focus (ACF) are considered pre-neoplasic lesions, ranging from hyperplasia to different degrees of dysplasia in the colon. This work aimed to evaluate and quantify the chemopreventive activity of Zingiber officinale essential oil in the colorectal region of Wistar rats.

MATERIALS AND METHODS

We extracted the essential oil from ginger rhizomes and carried out ACF induction, in rats, with 1.2 Dimethylhydrazine (DMH) at a 20 mg/kg dose. The experimental groups were GI (negative control); GII (positive induction control); GIII (DMH + essential oil); GIV (DMH +5-Florouracil) and GV (essential oil). The histological techniques used were methylene blue, hematoxylin-eosin (HE) dyeing, and immunohistochemistry (IHQ).

RESULTS

The major essential oil compounds were citral (17.25%), δ-citral (10.25%), camphene (9.55%), α-zingiberene (7.57%), nerol (6.37%) and plelandrene (6.83%). For the presence of AC or ACF, we did not observe them in GI and GV, while in GII and GIII, they were observed, in high values, in both regions, but only in the distal region, there was a significant difference between them. For GIV, for both regions, there were significant lower numbers of AC when compared to GIII. As observed, with HE, there were hyperplastic and dysplastic ACF in the proximal and distal portions of the colon. For IHQ analyses, there were positively PCNA antibody marked cells in all experimental groups. Yet, there was no significant correlation of mitotic index among them. Moreover, the results of GIII compared to GIV were very similar.

CONCLUSION

In this sense, the Zingiber officinale essential oil has good antioxidant potential because it presents a mixture of monoterpene and sesquiterpene compounds. Thus, it is able to develop a chemoprotective effect, as it presented similar results to the standard drug, showing cell proliferation control.

Effects of intratracheal Fusarium solani inoculation in immunocompetent mice

Fusariosis is an infection that is caused by fungi of the Fusarium genus. It is the second most common fungus that is associated with human fungal infections, usually in immunocompromised individuals. The incidence of such infections has been increasing, including in immunocompetent hosts. Studies of host-pathogen interactions are scarce, and the pathophysiology of the disease is unknown. One limitation of such studies is the lack of adequate techniques for mammalian infection, in which no standardized protocols have been established with fungi with a focus on the respiratory tract. The aim of the present study was to assess the first 24 h of infection after the intratracheal inoculation of F. solani microconidia in immunocompetent mice. Colony-forming units (CFU) were counted, and histopathological analysis was performed. Under conditions of high fungal burden, F. solani caused lethal tissue damage in the lungs. Under conditions of low fungal burden, the infection was not lethal, but several alterations of pulmonary tissue and the presence of the fungus in the lungs were observed. No evidence of fungal dissemination was found in the kidneys, spleen, liver, or heart 24 h after infection. The present intratracheal model effectively established fungal infection and appears to be suitable for studies of Fusarium spp.

Photodynamic Therapy for the Treatment of American Tegumentary Leishmaniasis: Evaluation of Therapies Association in Experimentally Infected Mice With Leishmania (Leishmania) amazonensis

Introduction: American tegumentary leishmaniasis (ATL) is a zoonotic disease caused by protozoan parasites of the genus Leishmania that affects the skin and mucous membrane. Currently, the available drugs for the treatment are injectable, with side effects, long-term treatment regimen and there is the possibility of drug resistance. Thus, alternative therapies have been tested, including photodynamic therapy (PDT). We evaluated the efficacy of PDT on its own and associated with the prescribed ATL treatment. Methods: BALB/c mice were infected with Leishmania (Leishmania) amazonensis and divided into 6 groups: Gluc+PDT, treated with Glucantime® and photodynamic therapy (PDT) with methylene blue (MB)/red LED (light-emitting diode); Gluc, treated with Glucantime®; PDT, treated with PDT with MB/red LED; Ampho+PDT, treated with amphotericin and PDT with MB/red LED; Ampho, treated with amphotericin; and control, which were infected but not treated. Two treatment cycles were performed. After 165 days of infection, the parasite load was determined. Results: Statistical differences were not found (P>0.05) between measures of volume and thickness of the infected footpads in the treated groups when compared with the control group. However, there was a significant reduction (P<0.05) in the parasitic load of the popliteal lymph nodes of the Gluc+PDT, Gluc, PDT and Ampho groups when compared to the control group. In the histological analysis of the infected footpads, the Gluc+PDT group presented a smaller amount of amastigote nests and lower intensity of the mononuclear infiltrate when compared to the Gluc and PDT groups. Conclusion: The results showed that although there is no significant difference in the evaluations of footpad size (thickness and volume), there is a downward measurement tendency in the Gluc+PDT group, as it can be observed by volume data and corroborated by parasite negative load.

Protective Effect of Cymbopogon citratus Essential Oil in Experimental Model of Acetaminophen-Induced Liver Injury

To investigate the hepatoprotective effect of Cymbopogon citratus or lemongrass essential oil (LGO), it was used in an animal model of acute liver injury induced by acetaminophen (APAP). Swiss mice were pretreated with LGO (125, 250 and 500[Formula: see text]mg/kg) and SLM (standard drug, 200[Formula: see text]mg/kg) for a duration of seven days, followed by the induction of hepatotoxicity of APAP (single dose, 250[Formula: see text]mg/kg). The liver function markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transferase were determined to evaluate the hepatoprotective effects of the LGO. The livers were used to determine myeloperoxidase (MPO) activity, nitric oxide (NO) production and histological analysis. The effect of LGO on leukocyte migration was evaluated in vitro. Anti-oxidant activity was performed by assessing the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. LGO pretreatment decreased significantly the levels of ALT, AST and ALP compared with APAP group. MPO activity and NO production were decreased. The histopathological analysis showed an improved of hepatic lesions in mice after LGO pretreatment. LGO inhibited neutrophil migration and exhibited anti-oxidant activity. Our results suggest that LGO has protective activity against liver toxicity induced by paracetamol.

[American cutaneous leishmaniasis in municipalities in the northwestern region of Paraná State: use of remote sensing for analysis of vegetation types and places with disease occurrence]

American cutaneous leishmaniasis, an endemic disease in the northwestern region of Paraná, Brazil, is transmitted by phlebotomines to man and animals like dogs, armadillos, opossums and wild rodents. This disease has been occurring in places where forests have been felled and on the banks of rivers and lakes with arboreal vegetation, where man comes into contact with infected insects. This disease is a public health problem because of the occurrence of epidemic outbreaks throughout Paraná. Because of the importance of finding out about endemic areas, this study used epidemiological file data on patients attended between 1999 and 2004. These data were correlated with areas of forest felling that were identified by means of satellite remote sensing techniques and products. The results showed that the occurrences of cases in the municipalities of this region coincided with the presumed likely areas for patient infection.

Asexual recombination in a uvsH mutant of Aspergillus nidulans

Mutations in the gene uvsH of Aspergillus nidulans result in increased spontaneous chromosome instability and increased intragenic and intergenic mitotic recombination in homozygous diploids. The aim of the present work was to obtain a uvs mutant of A. nidulans and to use it for the isolation of asexual recombinants (parameiotic segregants). The mutant uvsH, named B511, showed normal frequency of meiotic recombination in sexual crosses and high frequency of parameiotic segregants in the parasexual crossings with master strains (B511//A757 and B511//A288). Asexual haploid recombinants (parameiotic segregants), diploid and aneuploid segregants were recovered directly from the uvs//uvs+ heterokaryons (B511//A757 and B511// A288). Parameiotic segregants originated through mitotic crossing-over and independent assortment of chromosomes.

Parasexuality in asexual development mutants of Aspergillus nidulans

The parasexual cycle with parameiosis has been characterized previously by the occurrence of genetic recombination and haploidization inside heterokaryotic hyphae prior to conidial formation. The aim of current research was to characterize, through genetic and cytological analyses, an asexual development mutant strain of A. nidulans and to use it to obtain parameiotic segregants. Analyses showed the medusa phenotype of the B84 strain, whose mutant allele was mapped in the chromosome I. The heterokaryons B84(med)//G422(med+) and B84(med)//G839(brl) were formed in liquid MM+2% CM and inoculated in the appropriate selective media. Two mitotic segregant groups were obtained: aneuploids and haploid stable recombinants. Mitotic segregants, wild-types, and developmental mutants, which did not produce new visible mitotic sectors in the presence of Benomyl and which showed normal meiotic behavior during the sexual cycle, were classified as parameiotics.

Parameiosis inAspergillus nidulans in response to doxorubicin

The recombinagenic effect of doxorubicin (an anticancer agent that impairs DNA synthesis and causes chromosome breaks) was used to induce parameiotic events in Aspergillus nidulans. Heterokaryons formed with master strains and uvs mutants were inoculated with and without doxorubicin. Haploid segregants (parameiotics and parents) and aneuploids were selected as heterokaryon-derived visible sectors. Among parameiotic segregants, recombinants by intergenic mitotic crossing-over and recombinants by chromosome-independent segregation were found. Whereas segregants of the former type were obtained only with doxorubicin, those of the latter type were recovered both with and without the drug.